What happened
The aircraft was returning to the airport following an agricultural spraying operation when the engine experienced a sudden loss of power. Unable to maintain altitude or continue the flight, the pilot executed an emergency landing in a flooded rice paddy adjacent to the airfield. The impact caused the aircraft to nose over, resulting in significant structural damage to the forward fuselage and landing gear.
The investigation
A post-accident examination of the engine revealed that the turbocharger impeller retaining nut had become loose. This mechanical failure allowed the impeller to move out of position, causing severe internal damage to the turbocharger assembly. The loss of boost pressure from the damaged turbocharger directly resulted in the engine quitting and producing no power.
Findings
The investigation determined that the primary factor in this accident was the mechanical failure of the turbocharger system. Specifically, the loosening of the impeller retaining nut led to catastrophic damage within the turbocharger unit. This hardware failure caused an immediate and total loss of engine power during a critical phase of flight, leaving the pilot with no option other than a forced landing in the nearby agricultural field.